Not applicable.
Not applicable.
The invention relates to a heating equipment portion, particularly for a motor vehicle water or air heating equipment, operated with liquid fuel, in the form of a supplementary heater or auxiliary heater with a burner and heat exchanger.
Known motor vehicle water or air heating equipments are supplementary heaters, which contribute to improving the heat supply to the vehicle interior and to the engine when the motor vehicle engine is running, or auxiliary heaters, which make a heat supply available to the vehicle also independently of the engine. The equipments are operated with liquid fuel, namely with the vehicle""s own fuel, diesel or gasoline.
Depending on the system, the equipments, because of the liquid fuel operation and the number of components (constructional size, production costs), are at present not unconditionally suitable for the smallest motor costs), are at present not unconditionally suitable for the smallest motor vehicles of the so-called mini type, which are particularly designed for a minimum fuel consumption.
The invention has as its object to provide a heating equipment portion, particularly for a motor vehicle water or air heating equipment of the kind mentioned hereinabove, which has a compact construction and can have versatile uses for a heating equipment.
The object of the invention is attained by a water or air heating equipment, operated with liquid fuel, of a motor vehicle, in the form of a supplementary heater or auxiliary hater with burner and heat exchanger wherein at least one portion of a fuel-operated heating equipment is provided as a constructional unit together with at least a portion of an electric heating equipment.
A feature of the invention is that at least a portion of a fuel-operated heating equipment is provided with at least a portion of an electric heating equipment, as a constructional unit.
The constructional unit preferably includes at least an electric heating loop oil and an inner or outer jacket portion of a heat exchanger of a fuel-opperated heating equipment, wherein the electric heating loop or coil extends substantially on the outer periphery of the inner jacket portion or on the inner periphery of an outer jacket portion.
The electric heating loop or coil can in particular be provided as an electric heating insert which includes a helicoid heating section arranged on or in the jacket portion, and a straight return section, the electrical connections being situated on the one axial side of the jacket portion.
A simple structure results when the jacket portion has a substantially smooth outer or inner jacket surface.
However, an axial groove in which the return section of the electric heating insert is received is preferably provided in the otherwise smooth jacket surface, along a generating line of the jacket surface. The axial groove provides for an exact peripheral and axial fixation of the electrical heating insert with respect to the jacket portion.
The electrical heating loop or coil can here be constituted as slightly resiliently prestressed in the radial direction, or self-fixing, against the jacket portion.
The return section can have curved end sections which form axial fixation aids for the electrical heating loop or coil with respect to the jacket portion.
The helicoid heating section is preferably matched in shape to the respective outer or inner contour of the jacket portion and forms, with a jacket portion used as the heat exchanger of a fuel operated heating equipment, water or air guiding ribs for a medium (water or air) to be heated as it flows through, also in particular when the jacket surface (except for the axial groove) is smooth.
The electrical connections are in particular passed through a housing end side of a heating equipment, are fastened to the housing end side, and are accessible from outside for a current connection to a current source, in particular a motor vehicle battery.
The constructional unit can have temperature sensors which can be used both for an electric and also for a fuel-operated heating equipment.
The constructional unit is preferably interchangeable in a heating equipment and can be replaced, for example, by a conventional motor vehicle heating equipment heat exchanger.
The versatility of the heating equipment portion according to the invention results particularly from the fact that the constructional unit can be used, on the one hand exclusively as an electric heating equipment, and on the other hand exclusively as a heating equipment operated with liquid fuel, but also that a combined operation is possible in which the constructional unit functions in a heating equipment as a heating device which is operated both electrically and also with liquid fuel. The last-mentioned variant of the invention has a large heat delivery and in particular makes possible a mixed operation or a two-stage operation with only a single control cost. With the second heating stage, the electric heating can easily be switched on in addition when operating with fuel, or vice versa, fuel operation can be switched on in addition when in electric base mode operation.
Thus according to the invention an electric heating insert is combined with a well-established fuel-operated heating equipment insert. The motor vehicle heating equipment containing the said insert is nevertheless compact. The choice of heating energy is basically free. Operation with the selected energy can be arranged in a heating equipment with the aid of simple constructional means.
Thus, for example, a well-established fuel-operated heating equipment portion can be directly made accessible to the smallest type of motor vehicle, and can then be operated with electrical energy by means of the built-in heating coil.
The said well-established fuel-operated heating equipment is the xe2x80x9cheat hangerxe2x80x9d, which of course does not have the function of a heat exchanger when operated electrically, but rather the air or water flowing through is then directly heated by the heating coil.
The xe2x80x9cheat exchangerxe2x80x9d has, for example, a pot form, with the water (or air) to be heated passing through the peripheral jacket and pot floor. In electric heating operation, the heating coil directly heats the water (or air) flowing through on the jacket side. The hollow interior of the pot of the xe2x80x9cheat exchangerxe2x80x9d contains no components and is covered at the side opposite the pot floor by a cover.
For the conversion to liquid fuel operation, the said cover is removed and the combustion chamber is installed inside the pot; in particular, the flame tube of the burner is introduced into the pot interior and flange-mounted axially (together with further parts such as a combustion air fan, etc.).
No parts have to be interchanged on changing over from electric heating to fuel heating. Consequently no parts can be lost. The base body, i.e., the jacket portion or the heat exchanger and heating coil, remains or remain in the place in the motor vehicle where they are built in.
If a user of a smallest type motor vehicle later wishes to change over its electric heating according to the invention to operation with diesel or gasoline and use the advantages of the known fuel-operated motor vehicle heating equipments, this is possible in a cost-efficient manner, but is not possible with known electric heaters.
If electric heating is to be completely dispensed with, the heating coil and xe2x80x9cheat exchangerxe2x80x9d can of course be replaced by a conventional heat exchanger with water-guiding ribs.